The present invention relates to a control apparatus that includes an operator member movable or displaceable relative to one or more displacement axes, and more particularly to a technique for imparting reactive forces to the operator member in response to operation by a human operator. The present invention can be suitably used not only for performance input operation in electronic musical instruments but also for input operation in various games, CAD designing, etc.
In Japanese Patent Application Laid-open Publication No. HEI-10-177387, there is disclosed an apparatus which includes an operator member operable by a human operator, an actuator for moving the operator member and a sensor for detecting a position etc. of the operator member. In the apparatus, driving of the actuator is controlled so as to impart the operator member with reactive forces responsive to input operation, by the human operator, of the operator member.
In the apparatus disclosed in the publication, the intensity, direction, etc. of the reactive forces to be imparted to the operator member are controlled by driving the actuator in accordance with information based on operation actually performed by the human operator on the operator member, such as position information, velocity information and acceleration information, and thus a reactive force, only corresponding to (proportional to) an actual amount of operation by the human operator, is always given to the human operator. Therefore, where pitch, color, volume, etc. of tones are to be controlled in accordance with detected position information output from a sensor, it would be very difficult for the human operator to properly perceive and recognize correlation between the reactive force imparted to the operator member in accordance with a current operating amount and control amounts of the tone pitch, color, volume, etc. to be controlled in response to the current operating amount. Namely, the human operator has no choice but to repeat trial and error, in order to effectively learn how to properly operate the operator member (i.e., correlation between the operating amount perceived through the reactive force and the control amounts corresponding to the current operating amount), which unavoidably results in poor efficiency in learning how to properly operate the operator member. Particularly, where the operator member is in the form of a multi-axially operable operator member, such as a joystick, it tends to be even more difficult for the human operator to accurately ascertain whether or not the operator member has been operated to an operating amount or operating position as desired by him or her, because, in this case, positional operation of the operator member becomes significantly complicated.